Vehicle drawbar structure



April 1966 D. s. WEISS 3,244,435

VEHICLE DRAWBAR STRUCTURE Filed Aug. 19, 1963 INVENTOR.

DEWEY S. WEISS A T TORNE KS United States Patent 3,244,435 VEHICLEDRAWBAR STRUCTURE Dewey S. Weiss, 3506 SE. Bybee Blvd, Portland, Oreg.Filed Aug. 19, 1963, Ser. No. 302,921 8 Claims. (Cl. 280-435) Thisinvention relates to a drawbar structure and particularly one in whichan elastomer shock absorbing member is incorporated in the drawbarstructure.

In prior drawbar structures of the above type, such as disclosed in myown Patent 2,428,950, a nut has been employed to draw a tapered pinfarther into an interiorly tapered elastomer sleeve to effect thedesired anti-play compressive fit between the sleeve and related parts.It

is frequently necessary to relieve the compression on said sleeve toenable the tongue of the drawbar structure to be raised to anout-of-the-way inoperative position. For instance, such a disposition ofthe tongue is required in order to move a trailer onto a truck bed fortransporting the trailer back empty. To relieve the compression in myprior construction, the nut was loosened to allow retracting axialmovement of the tapered pin. Occasionally, when the tongue wassubsequently lowered to its operative position, the driver failed totighten the nut. This allowed the nut to work itself off the pin, andthe pin to Work itself out of the sleeve, to allow .a separation of thedrawbar structure with resultant damage to the trailer.

It is a main object of the present invention to provide a drawbarstructure of the general type under construction, in which thecompression on the elastomer sleeve can be decreased to allow readymovement of the tongue, without any danger or likelihood of separationof the drawbar structure.

A more specific object of the invention is to provide a drawbarstructure as above described in which the fit of the elastomer sleevewith the related parts is adjusted by a radially movable shoe.

Various other objects of the invention will be apparent fromthefollowing description taken in connection with the accompanyingdrawings wherein:

FIG. 1 is a somewhat diagrammatic view showing a drawbar structure ofthe present invention connecting a towing vehicle to a towed vehicle;

FIG. 2 is an enlarged plan view of a hinge structure of the drawbarstructure;

FIG. 3 is a vertical section taken along line 3-3 of FIG. 2;

FIG. 4 is a side elevation view of the hinge structure taken in thedirection of the arrows 4-4 in FIG. 2; and

FIG. 5 is a fragmentary vertical section taken along line 55 of FIG. 3.

Referring to FIG. 1, a towed vehicle 11 is connected by a drawbarstructure 13 to a towing vehicle 15. The drawbar structure incorporatesthe concepts of the present invention and includes a tongue in the formof a pair of rearwardly diverging legs- 17 carrying an eye 19 at thefront end thereof for engagement with a pintle or prong 21 on the-towingvehicle. At the rearv end of each of the legs 17 is a hinge structure orassembly generally entitled 23. Since the hinge structures are ofidentical construction, a descriptionof only the lefthand structure willbe given.

Referring to FIGS. 2, 3 and 4, the hinge structure or assembly includesa clevis-like bracket 31 for mounting on the towed vehicle 11. Inaccordance with usual practice, the bracket is welded to the forward endof the towed vehicle. The hinge structure further includes an annularhousing member or eye 33 which has a pair of spaced lugs 35 forembracing the rear end of the legs 17. The lugs 35 are welded to theassociated leg 17 in any of several desired positions, as indicated inFIG. 1.

3,244,435 Patented Apr. 5, 1966 It is apparent from FIG. 2 that the eye'33 is narrower than the recess between the legs of the clevis-likebracket member 31 so that it is spaced from each leg. Passing throughthe bracket 31 and the eye 33 is a cylindrical pin 37. The legs 31a ofthe bracket are split, as shown in FIG. 4, so that a nut and bolt unit39 can be employed on each leg to clamp the pin 37 securely in place andto the bracket 31. A pair of tubular elastomer sleeves 41 are disposedbetween the eye 3'3 and the pin 37. The sleeves are separated from eachother by an arcuate rib 33' (FIGS. 3 and 4) formed interiorly on the eye33. The rib 33' maintains the eye 33 in spaced axial relation withrespect to the legs of the bracket 31. Each sleeve has an interiordiameter slightly larger than the exterior diameter of the pin 37, tohave a sliding fit thereon. Each sleeve has a cylindrical exteriorconfiguration which has a sliding fit within the bore of the eye 33. Thebore of the eye, which is given the reference numeral 331:, is ofcylindrical configuration except that the bore is recessed at 331') toaccommodate a shoe 43 of arcuate configuration. The recessing at 33bprovides stop surfaces Soc next to the circumferential ends of the shoe43 so that the shoe is prevented from circumferential movement. The shoehas an arcuate rib 43' forming a continuation of rib 33'. Rib 43'prevents shifting movement of the shoe in a direction parallel to theaxis of the pin 37.

Threaded into the eye 33 are a pair of adjustment bolts 45 which havetheir inner ends bearing in recesses 43a formed in the shoe 43. Jam nuts47 are provided on the adjustment bolts to hold them in desiredpositions of adjustment.

In operation, the bolts 45 are threaded inwardly to achieve a desiredcompressive fit of the sleeve 41 between the eye 33 and the pin 37. Acompressive fit is desired in order to avoid loose play in the drawbarstructure. Despite the compressive fit, the drawbar structure does havea shock absorbing ability which is desirable. The compressive fit of thesleeve between the pin 37 and the eye 33 does, however, prevent thetongue '17 from being readily swung upwardly to an inoperative position,or at least if the tongue can be so moved, there might be a residualforce tending to flip the tongue downwardly again.

To allow the tongue to be so freely moved, the jam nuts 47 can beloosened and the bolts 45 also loosened to relieve the pressure on theshoe 43 and thus relieve the pressure on the sleeve 41. Now, it is veryeasy to swing the tongue to any desired position. Despite the fact thatthe pressure has been relieved upon the shoe 43, there is still a solidconnection of the drawbar structure and no danger whatsoever of thedrawbar structure becoming separated because even if the bolts 45 worktheir way out of the eye 33, the only result will be the presence ofplay in the drawbar structure.

Having described the invention in what is considered to be the preferredembodiment thereof, it is desired that it be understood that theinvention is not to be limited other than by the provisions of thefollowing claims.

I claim:

1. A drawbar structure for connecting a towing to a towed vehic'le,

comprising a tongue having at one end at least one hinge assembly formounting on the towed vehicle and having at its opposite end means fordetachable connection to the towing vehicle,

said hinge assembly including a clev-is-like bracket for mounting on thetowed vehicle,

an eye on said tongue, said eye comprising an integral unbroken annularelement,

vehicle 3,244,435 3 r a .pin extending through said eye and bracket andseand screw means on said eye engaging said shoe and cured to thelatter, operable when actuated one way to force said shoe a tubularelastomer sleeve disposed between said pin inwardly or when actuated theopposite way to allow and said eye, said shoe to move outwardly. andmeans separate from said eye for varying the con- 5 5. A drawbarstructure for connecting a towing vetact pressure between the sleeve onone hand and hicle to a towed vehicle, the eye and pin on the other toattain varying resistcomprising a tongue having at one end at least oneance forces to the pivoting of the tongue about the hinge assembly formounting on the towed vehicle axis of said pin. and having at itsopposite end means for detachable 2. A drawbar structure for connectinga towing ve- 1 connection to the towing vehicle, hicle to a towedvehicle, said hinge assembly including a clevis-like bracket comprisinga tongue having at one end at least one for mounting on the towedvehicle,

hinge assembly =for mounting on the towed vehicle an eye on said tongue,and having at its opposite end means for detachable a cylindrical pinextending through said eye and connection to the towing vehicle,bracket, said hinge assembly including a clevis-like bracket for saidbracket having, split portions with means for mounting on the towedvehicle, tightening the same around said pin to prevent an eye on saidtongue, said eye being of ring shape, movement of said pin relative tosaid bracket, a pin extending through said eye and bracket and seatubular elastomer sleeve disposed between said pin cured to the latter,0 and said eye, tubular elastomer sleeve means disposed between said ashoe between said sleeve and said eye, said sleeve havpins and said eye,ing a cylindrical interior surface slidably receiving a shoe betweensaid sleeve means and eye, said shoe said pin and a cylindrical exteriorsurface,

being a member separate from said eye, said eye having a cylindricalinterior surface to slidand means for moving said shoe toward said pinto vary bly receive Said Sleeve,

the ontact pressure between said sleeve means and said cylindricalinterior surface Of said eye being IC- said eye and pin to attainvarying resistance forces to the pivoting of the tongue about the axisot said pin.

cessed to accommodate said shoe and provide stop surfaces at thecircumferential ends of said shoe to prevent circumferential movement ofsaid'shoe rela- 13. A drawbar structure \for connecting a towing vehicletiifi t0 Said y to a towed vehicle, and screw means on sat-d eyeengaging said shoe and comprising a tongue having at one end at leastcneoperable when actuated one way to force said shoe hinge assembly formounting on th t d hi l inwardly or when actuated the opposite way toallow and having at its opposite end means for detachable 531d ShoemoVfi 'i connection to the towi hi l 6. A drawbar structure forconnecting a towing vesaid hinge assembly including a clevis-likebracket for hlcle to Fob/6d l o ti on th m d hi l comprising a tonguehaving atone end at least one an eye "on said tongue, said eye being acontinuous unhlnge astsembly f0? ng 0n the towed vehicle interruptedannular member, and having at its opposite end means for detachable a13in extending through said eye and bracket and 46 .COHZZRZCUOQ to thetowing vehicle,

i d b h latter, said hinge assembly including a clevis-like bracket fortulbular elastomer sleeve means disposed between said mountmg 9 the wW@dVeh1c1e,

i d id eye, an eye on said tongue, said eye being of ring shape, a Shoebetween said slegve means and eye, a pin extending through said eye andbracket and remeans \for moving said shoe toward said pin to vary the 4tamed by the latter contact pressure between said sleeve means and saida tubular elastomer Sleeve (imposed between send pm eye and pin toattain varying resistance forces to the q a sald h bA 3 hp pivoting 0fthe tongue about flua axis of Said Pin, an means. or vargrng t e contactpressure etwcen t c and stop means for preventing circumferentialmoveslefive one h i the eye and pm on ment of saidshoe relative to Said59 to attain varying resistance forces to the pivoting 4. A drawbarstructure for connecting a towing vehicle the tongue abqut the axls ofsaid to a towed V Chi C16, said eye having a pair of tongue membersreceiving lug comprising a tongue having at one end at least oneportions for Embracing an elongate tongue,membef hinge assembly formounting on the towed vehicle r a adaptd to accommodate Sal/9'31anglfiuar,pos" and having at its Opposite 6nd means for detachable 5otionsof said tongue member relative to said pin. conngction to thetowing vehicle 7. A hinge assembly for a drawbar structure adapted saidhinge assembly including a clevis-like bracket for for cmmectmg a towmgVehicle a towed which mounting on {he {owed vehicle, 7 wherein saiddrawbar structure includes a tongue, an eye on i tongue, said hingeassembly including a clevis-like bracket for a cylindrical pin extendingthrough said eye and bracket 60 mmlming 0n the towed Vehicle:

and secured to the latter, an eye on said tongue, said eye comprising anintegral a tubular e'lastomer sleeve disposed between said pin endless Oe-piece nn l r m m and said eye, a pin extending through said eye andbracket and re a shoe between said sleeve and said eye, tained' by thelatter, said sleeve having a cylindrical interior surface slida tubularelastorner sleeve disposed between said pin ably receiving said pin anda cylindrical exterior surand said eye, i306, and means carried by said,eye but otherwise independsaid eye having a cylindrical interior sunfaceto slidt thereof for a i h Contact pressure y Twelve said Sleeve, tweenthe sleeve on one hand. and the eye and pin Said Cylindrical interiorSurface of said W being on the other to attain, varying resistanceforces to cessed to accommodate said shoe and provide stop the pivotingof the tongue about the axis of said pin, surfaces at thecircumferential ends of said shoe to S. A hinge assembly for a drawbarstructure adapted prevent. circumferential movement of said shoe relaforconnecting a towing vehicle to a towed vehicle,

live to Said y wherein said drawbar structure includes a tongue,

said hinge assembly including a clevis-like bracket for mounting on thetowed vehicle,

an eye on said tongue,

a cylindrical pin extending through said eye and bracket,

said bracket having split portions with means for tightening the samearound said pin to prevent movement of said pin relative to saidbracket,

a tubular elastomer sleeve disposed between said pin and said eye,

a shoe between said sleeve and said eye, said sleeve having acylindrical interior surface slidably receiving said pin and acylindrical exterior surface,

said eye having a cylindrical interior surface to slidably receive saidsleeve,

said cylindrical interior surface of said eye being recessed toaccommodate said shoe and provide stop surfaces at the circumferentialends of said shoe to References Cited by the Examiner UNITED STATESPATENTS 1,749,335 3/1930 Geyer.

2,428,950 10/1947 Weiss 280485 2,467,530 4/1949 Johnson 280-4852,856,216 10/1958 Witzel 28787 2,996,313 8/1961 Harbors et al. 280485LEO FRIAGLIA, Primary Examiner.

1. A DRAWBAR STRUCTURE FOR CONNECTING A TOWING VEHICLE TO A TOWEDVEHICLE, COMPRISING A TONGUE HAVING AT ONE END AT LEAST ONE HINGEASSEMBLY FOR MOUNTING ON THE TOWED VEHICLE AND HAVING AT ITS OPPOSITEEND MEANS FOR DETACHABLE CONNECTION OF THE TOWING VEHICLE, SAID HINGEASSEMBLY INCLUDING A CLEVIS-LIKE BRACKET FOR MOUNTING ON THE TOWEDVEHICLE, AN EYE ON SAID TONGUE, SAID EYE COMPRISING AN INTEGRAL UNBROKENANNULAR ELEMENT, A PIN EXTENDING THROUGH SAID EYE AND BRACKET ANDSECURED TO THE LATTER, A TUBULAR ELASTOMER SLEEVE DISPOSED BETWEEN SAIDPIN AND SAID EYE, AND MEANS SEPARATE FROM SAID EYE FOR VARYING THECONTACT PRESSURE BETWEEN THE SLEEVE ON ONE HAND AND THE EYE AND PIN ONTHE OTHER TO ATTAIN VARYING RESISTANCE FORCES TO THE PIVOTING OF THETONGUE ABOUT THE AXIS OF SAID PIN.